Merge remote branch 'origin/gallium-st-api'

diff --cc src/gallium/state_trackers/dri/dri_context.c
Simple merge

diff --cc src/gallium/state_trackers/glx/xlib/Makefile
Simple merge

diff --cc src/gallium/targets/libgl-xlib/xlib.c
Simple merge

diff --cc src/mesa/SConscript
Simple merge

diff --cc src/mesa/sources.mak
Simple merge

diff --cc src/mesa/state_tracker/st_cb_readpixels.c
Simple merge